How to do it: Start with two layers of your basecoat for an opaque finish. Once your nails are dry, dip a balled-up bit of plastic wrap in light grey polish and gently dab your nails with it. Once that’s dry, take a special brush, dip it in black polish, and paint swirly accents to make them look like marble. Seal everything with a clear topcoat. Eat your heart out, Michelangelo.